It is becoming apparent that two Fusarium mycotoxins, vomitoxin and zearalenone, frequently appear in wheat and corn produced throughout the temperate regions of North America. Vomitoxin, a trichothecene, is a protein synthesis inhibitor while zearalenone functions as an estrogen. The relative stability of these toxins to inactivation during milling and processing allows for their entry into the human food supply. Based on related studies with other trichothecenes and estrogens, a possible adverse effect of vomitoxin and zearalenone may be modification of normal immune function. In view of the potential for human exposure to these compounds, it is imperative that a comprehensive data base regarding their immunotoxicity be available. The aims of the proposed research will be therefore the asess whether growing female mice exposed to dietary vomitoxin and/or zearalenone exhibit significant suppression of host resistance, humoral immunity, cell-mediated immunity, and macrophage function when compared to animals fed identical toxin-free rations. This assessment will be based on an in vivo immune function survey that includes the following assays: (1) organ/body weight ratio, (2) hematologic profile (3) total immunoglobulins (4) humoral response to thymus dependent and thymus independent antigens (5) delayed hypersensitivity, (6) resistance to Listeria monocytogenes, and (7) endotoxin hypersensitivity. It is believed that this research will provide answers to fundamental questions regarding the deleterious effects of Fusarium mycotoxin-contaminated foods on human health and immunity and be a basis for further investigations of the biological mode of action of these common fungal toxins.